Sheet metal can and rip strip therefor



June 25, 1935. Y A. G. HOPKINS ,0

SHEET METAL CAN AND RIP STRIP THEREFOR Filed July 27, 1932 M 2 1 2 '4 a4 if i; 1': "'3; ,4 Z6 42' g 28 so ATTORNEYS 42 Alli 54 mu 1 NH 28 1 E l2 INVENTOR Arrhur G.Hopkms M n-" I PM Patented June 25,1935 A UNITED STATES PATENT OFFICE SHEET METAL CAN AND RIP STRIP THEREFOR Arthnr G. Hopkins, Maspeth, N. Y., assignor to National Can Company, a corporation of Delaware Application July 27,1932, Serial No'. 025,090 3 Claims.. (01. 220-54) This invention relates to metallic receptacles, resides in the application of either or both of the and more particularly to sheet metal cans proforegoing features of invention to a particularly vided with a rip strip or tearing strip for opendesirable form of double closure can of the gening t Same. eral type disclosed and claimed in my copending 5 Many kinds of metallic containers are, known application Ser. No. 463,411, filed June 24, 1930 5 which are provided with.a rip strip, ordinarily for Sheet metal can". This can is desirable in defined by a pair of score lines, for opening the type because when the tearing strip is removed container. Considerable difliculty is experienced there is left a slip cover adapted for use with the by reason of the rip strip tearing transversely can until the contents have been consumed, and across its width, thereby preventing further 'openat the same time the can is not reduced in height, 10 ing of the can. This difliculty frequently arises and the interior surface or wall of the can is regardless of the nature of the can construction formed of a continuous, smooth, and uninterand may be caused, for example, by hasty or unrupted single piece of metal. Still another obeven manipulation of the key used to roll up the ject of the present invention as applied to such rip strip, or by imperfections in the score lines, a double closure can is to so seal the can that the 15 defining the rip strip, or by flaws in the metal. slip cover remaining after removal of the rip The difiiculty is particularly common in containstrip will fit the container with a snug and sealers having the rip strip located on a wall which ing fit so that the can will be nearly if not peris drawn up from a fiat piece of metal, because fectly air-tight for the protection of the remainin such case the drawing operation tends to cause ing contents of the can after some of the con- 20 a seaming or mining of the metal which extents have been removed. tends transversely of the rip strip and weakens In consequence of the various foregoing and and predisposes the rip strip toward this undeother features of the present invention which will sirable crosstearing. subsequently appear, it is possible to produce One primary object of the present invention is within the present vacuum container a vacuum 25 to overcome this difiiculty and to strengthen and far higher than any heretofore employed for reinforce the rip strip against cross tearing, and metal package or metal can purposes. In fact further to provide means acting as a guide or the vacuum producible and maintainable by the track for insuring smooth and even rolling up of sealing methods used is so high that the can is apt the rip strip, and to further insure that the sevto be collapsed inwardly by the surrounding air 30 ered edges left after rolling up the rip strip will pressure; and it is still another object of the be smooth and continuous rather than ragged present invention to guardagainst this possibility and dangerous. a and to so improve the can construction that it will For rolling up the rip strip it customarily is be greatly stiflened and strongly resistant to provided with a tab which is raised from the surcollapse under high vacuum. 35

face of the container and adapted to be received To the accomplishment of; the foregoing and by an appropriate key for rolling' up the rip such other objects aswill hereinafter appear, my strip. Where the tab need not be sealed, its pro-' invention consists in the sheet metal can elevision is a relatively simple matter for it is only ments and their relation one to the other, as necessary to strike up from the surface of the hereinafter are more particularly described in container wall an appropriately shaped tab of the specification and sought to be defined in the metal. Where, however, the package must he claims; The specification is accompanied by a sealed against leakage at the tab, considerable drawing in which:.

diificulty' and expense are occasioned, for it then Fig. 1 is a front elevation of one form of double P is necessary to slit the container wall and insert closure metal can embodying features of my ina taband solder the same in place, or to solder -vention; or weld a tab on the outside of the container Fig. 2 is a horizontal section through the tab, wall. A further and important object of the and is taken in the plane of the line 2--2 in present invention resides in the provision of a Fig. 1;

solderless sealed tab which will not necessitate Fig. 3 is a vertical section through the upper the insertion or addition of metal other than portion of the can, and is taken in the plane of the normal continuous container wall; and furthe line 3-4 inFig. 1; therto provide an appropriate key for the utiliza- Fig. 4 is a side elevation of the upper portion tion of-such an improved tab. of a modified form of double closure can em- Still another objectof the present invention 'ploying my novel solderless sealed tab; 5

Fig. 5 is a horizontal section through the tab, and is taken in the plane of the line 5-5 in Fig. 4;

Fig. 6 is a vertical section through the tab, and is taken in the plane of the line f55 in Fig. 4;

Fig. '7 is a section similar to Fig. 5, showing the condition of the tab after it has been pried open; and

Fig. 8 is a perspective view of a key specially modified and adapted for use with my solderless sealed tab.

A number of features of the present invention, such as my improved rip strip and my improved solderless sealed tab, are applicable to innumerable forms'of metal container, but for purposes of illustration are here shown applied to an improved form of double closure can two modifications of which are illustrated in the accompanying drawing. Referring to the said drawing, the can selected by way of illustration comprises a generally cylindrical can body it which is pref-1 erably made of a single continuous piece of metal. The can is further provided with an exterior onepiece top Hi and a conventional bottom it, the latter preferably being applied after the can has been filled and subjected to a vacuum, all in the usual manner.

The cylindrical can body i2 is provided with a rolled top edge i8 and an intermediate circumferentially projecting bead 2d, while the cover it may be and preferably is dished, as is indicated in Figs. 3 and 6, to form a cover wall 22 and a marginal groove 2Q adapted to mate with and fit over the rolled upper edge it of the can. The cover M further comprises a depending side wall 26 and a flanged bottom edge which overlies and mates with the peripheral bead 2d of the can body, the bottom edge 28 and bead 2t preferably being not only rolled together into a permanent lock seam joint, but also being rolled downwardly, as is clearly indicated in Fig. 3, in order to force the marginal groove 26 of the cover into close and sealing engagement with the rolled edge if! of the can body. A rip strip tti is provided on the depending wall 25 of the top it, said rip strip being defined by a pair of score lines 32 extending peripherally around the wall. It will be evident that upon rolling up and removing the rip strip 30, the upper portion'of the top it may then be removed and used as a slip cover in association with the can body; and it will further be evident that this slip cover will fit snugly on the rolled upper edge E8 of the can body. There is no decrease in height of the can, and the interior of the can is formed of a smooth and continuous single piece of metal.

,The seal at the top of the can between the rolled edge l8 and the groove 23 may, if desired, be made the only and primary seal for the top of the can, in which case a sealing liquid or paste may be applied in the groove 2%, as is indicated at 36 in Fig. 3. In such case it is not necessary for the tab 36 of the rip strip to be sealed, and a simple outwardly struck tab such as is illustrated in Figs. 1 and 2 may be employed. What is even more important, however, is the fact that-the sealing compound, particularly if of the elastic rubberlike type now frequently employed, may be relied upon to help beneficially seal the container during its subsequent use after it has been opened by removal of the rip strip 38, that is, the sealing material 34 remains in the groove 26 and acts as a washer or gasket for helping make the joint between the slip cover and the can body an airtight one.

aooaore It will be understood, however, that if desired the permanent vacuum seal of the container may be made at the rolled lock seam joint 20, 28, and in such case sealing fluid or paste may be applied at that joint, if desired, and such a construction is illustrated in the modified form of container of Figs. 4-7, the presence of the sealing compound at the lock seam joint 20, 28 being clearly evident at 38 in Fig. 6. With this construction, it is evident that an open tab such as the tab 36 should not be employed, but rather a sealed tab, and in such case I prefer to use a novel form of solderless sealed tab such as the tab iii shown in Fig. It will further be appreciated that if desired sealing fluid or compound may be applied both in the groove 26 and in the lock seam joint 20, 28, in which case a double seal will be provided to guard against leakage before the container is first opened, while an improved seal will be maintained by the slip cover during its normal use after the container has been opened.

Considerable difiiculty arises due to failure or cross tearing of a rip'strip regardless of the type of packageon which it is used and particularly when used on a wall of metal which has been drawn in a direction transverse to the rip strip, as is here exemplified by the depending wall 25 of the top M, which is drawn in a direction normeal to the longitudinal direction of the rip strip til. I have found that this long-existent difiiculty with rip strips may be remarkably effectually overcome by the simple expedient of providing the rip strip with one or more and preferably two beads or channels 42 which greatly stifien and strengthen the rip strip by reason of the channel effect created thereby, and which act as guides or tracks whenrolling up the rip strip, and thereby cause the rip strip to roll up in a straight and even manner. These beads 42 are preferably struck outwardly from the rip strip and preferably extend parallel to and within but adjacent to the score lines 32. This location of the strengthening beads is apparently the most favor able one, although I have found that considerable variation in location may be made without losing the beneficial effect of such beads in the way of strengthening the rip strip against cross tearing. Each of the beads acts as a definite interruption to any transverse tearing stress such as might be caused by uneven manipulation of the key, or by reason of graining of the metal due to the drawing operation. Furthermore, these beads stiffen the rip strip and strengthen it in 0nd form of container, that illustrated in Figs.

4-7. This tab is indicated at M and is formed simply by scoring the continuous wall of the metal container with a plurality of score lines Ml and (it for outlining and defining the tab 40. Inasmuch as these score lines do not extend entirely through the metal, the tab is sealed against leakage. A key for winding up the rip strip is illustrated in Fig.8 and is conventional in comprising a slotted stem iii; and a handle 50 for rotating the.

same, but differs from the conventional key in be ing provided with a chisel edge 52 properly dimensioned for use with the tab M. It will be evident that by forcing the chisel edge 52 of the key 50 into the incised or scored metal, particu-.

P bulge 54 formed on the side wall of the container.

, be secured thereto by a drop of solder or other The protuberance 54 provides a space between the tab'4ll and the inner wall or can body l2, so that the chisel edge of the key is readily forced inwardly at the score line .46, thereby exposing the end of the tab so that it may be lifted outwardly.

It should also be noted that the score line 46 is preferably made arcuate and extends for a substantial distance beyond the outlined the tab means. This is indicated by the portion of the key 50 visible in Figs. 3 and 6 showing the soldering of the key at the point'58,to the cover wall 22 of the can. To open the can, the key is lifted 'andthus freed and separated from the top of the can, after which the chisel end 52 is inserted in the recess 56 shown in Fig. 5, and forced inwardly. The metal at the point "56 then yields inwardly, as is shown in Fig. '7, after which the chisel end of the key passes directly underneath the tab 40 so that the latter is readily lifted or raised outwardly, as is also shown in Fig. '7. The tab is then passed through the key and the key rotated to roll up and remove therip strip. The key and rip strip may then be discarded, the can thereafter being used as a simple slip cover can.

The type of seal obtainable with this metal can,

particularly the seal indicated at 34 in Fig. 3 or at 38 in Fig. 6, is an excellent seal permitting evacuation of the container to a very high degree heretofore not attempted The evacuation may be readily carried to a point resulting in collapse of the container; and to-guard against this I stiffen the cylindrical wall of the container by the, 'use of peripheral channels or beads. Thus, in

Fig. 1, the container body I2 is provided with two intermediate outwardly struckchannels or beads 60 and 62 which extend-peripherally around the cylindrical container-wall and stiffen the same against collapse. It should also be keptin mind that the container wall is veryfgreatly stifiened and strengthened by the permanent lock seam 2U, 28, for this is made up of a double thickness of metal, and the resulting seam thus acts to strengthen the container against collapse under vacuum. Furthermore, this rugged strengthening seam is of value even after the can has been opened because it serves to preserve and maintain the true circular configuration of the upper portion 'of the can which mates with the slip cover.

It is believed that the mode of constructing and using my improved metal can, and the several individual features thereof, as well as the many advantages thereof will. .be apparent from the foregoing detailed description. The improved rip prevent cross tearing; to stiffen the rip strip and o to insure even continuous rolling of the same; aswell as to obtain a smooth and clean severance or separation of the rip strip from the remaining me'tal. The solderless sealed tab makes possible the provision of a tab which is formed out of the continuous metal wall of the container, without slitting and inserting or adding additional pieces of metal, and without soldering, welding, or similar operations such as have heretofore been necessary when it was desired toprovide a tab while at the same time sealing the container against leakage or air admission. The particular double closure can illustrated possesses numerous and manifest advantages many of which need not be outlined in detail, and some of'whi'ch are common to the containers here shown and that disclosed in my prior application already referred to. However, in addition it should be noted that a secure seal may be obtained by the use of a sealing compound at the top edge of the container, thereby; dispensing with the necessity for sealing the rip strip tab. Furthermore, the sealing compound remains in place and acts as a washer or gasket for insuring an excellent seal between the slip cover and the can during normal use of the can after it has been opened.

If, however, it is preferred to obtain a vacuum seal at the lock seam joint between the edge of the top and the head on the can body, such an arrangement also may be employed, and in that case it becomes necessary to seal the rip strip tab. For this purpose my new and improved solderless sealed tab is, of course, desirable. It will also be appreciated that sealingcompound may be employed both at the top and intermediate joints of the container, thereby'providing a double seal and a high vacuum protection. In any of the three cases the vacuum obtainable is so high as to tend to cause collapse of the container; and to guard against this the container may be additionally reinforced by one or more stiffening beads or channels. From the standpoint of the packer, no disadvantage or complication results because the can is manufactured with its top and without its bottom, and is filled in inverted condition and closed and sealed at the bottom by the ordinary machinery already used by the packer. The consumer, of course, is presented with a greatly improved package making the container desirable for continued use until completely emptied.

It will be apparent that while I have shown and described my invention in preferred forms, many changes and modifications may be made in the structures disclosed without departing from the spirit of the invention, defined in the following claims. e

I claim:

1. A sheet metal container comprising a wall provided with a rip strip, said rip strip being defined by a pair of parallel score lines extendin around the wall and furtherincluding means to prevent tearing, said means consisting solely of 'a plurality of outwardly struck simple smooth including means'to prevent tearing, said means consisting solely of a pair of outwardly struck simple smooth elongated continuous beads or channels extending around the wall in' parallel relation to the score lines and within and closely adjacent to the aforesaid score lines.

3. A double closure sheet metal vacuum can comprising a can body, a one-piece drawn can top consisting of a cover wall and a, continuous depending side wall having its bottom edge sealed to the can body, the downwardly drawn depending wall of the can top being provided with a rip strip defined by a pair of parallel score lines ex- .l aooaoee tending peripherally around the wall, said rip strip further including a pair of outwardly struck simple smooth elongated continuous beads or channels extending along the rip strip in parallel relation to the score lines and within and closely adjacent to the aforesaid score lines in order to strengthen the rip strip against cross tearing.

ARTHUR G. HOPKINS. 

